Beloved author and teacher Jon Hassler, whose unconquerable will to write became as much admired as his novels steeped in small-town Minnesota, died early Thursday of a Parkinson's-like disease. He was 74.

In more than 15 novels, including "Staggerford" and "The Love Hunter," Hassler won a large and loyal following. Among his fans were Hillary Rodham Clinton, who twice invited him to the White House, and Angela Lansbury, who played his best-loved character -- the high-minded Agatha McGee -- in a TV movie.

With affection, intelligence and one eye always cocked, he offered the world a window on Minnesota, drawn from its ice houses, hunting shacks, senior citizen homes and church basements.

"He's really the best novelist we've had of ordinary life in Minnesota," said fellow writer and friend Bill Holm, of Minneota, Minn. "Jon's novels somehow included large swatches of life that nobody had captured -- or if they had tried to capture them, they did so to make fun of them or to reduce them in size."

Hassler, of Minneapolis, battled progressive supranuclear palsy for almost 15 years, a rare brain disorder that slowly stole his ability to write by hand, to speak or see clearly and, finally, to walk. But, fueled by sheer force of will and the love and support of his wife, Gretchen Kresl Hassler, he devised ways to keep at it.

A spirited problem-solver, Hassler wrote his most recent novels by "typing." His fingers, however, would fall haphazardly on the keyboard, and only he could read the resulting "gibberish." He'd whisper his translations of the typewritten pages to Gretchen, who would then retype them.

'He just kept going and going'

"Through all this, I loved him for his courage and his pluck," Gretchen Hassler said. "He just kept going and going. He had a book to finish, and, by golly, he finished it, too."

A new novel, "Jay O'Malley," was finished in the weeks before his death.

In spite of the physical and emotional challenges confronting them, both husband and wife were equally uncomplaining.

"Because it was a progressive illness, we had time to adjust all along the way," Gretchen Hassler said. "It never really became overbearing. What made it easy was one, he was the love of my life, and two, he was such an easy person, so sweet-natured."

Humor was the best medicine, Gretchen said.

"Why don't you ever swear?" she once asked him in exasperation after he took a nasty fall.

"Because you do it for me," he quipped.

Hassler was born on March 30, 1933, to Leo Blaise Hassler, a grocer, and Ellen Hassler, a teacher, of Staples, Minn. His career path took him from schoolteacher in Melrose to a regent's professor at St. John's University in Collegeville.

As he taught, he continued to write, with Agatha, the retired schoolteacher, starring in five of his novels. She more than any other character seemed to embody the author's Catholic, Midwestern and teacherly sensibilities. Indeed, Joe Plut, a former colleague at Central Lakes College in Brainerd, who taught Hassler's work, once said that the character was "part Jon, part his mother and part fiction."

She could be judgmental, shaming and scolding, but also compassionate and vulnerable. "She's one of the funniest characters in American literature," Holm said. "Here's this schoolmarm, this prissy, puritanical super-Catholic old maid, and she turns out to be one of the bravest and wisest characters in literature."

"He had skills that match with anybody, but because he had no pretension and because he didn't want to show off, he just told stories without gimmicks and let the characters speak for themselves," Russo said.

Longtime friends and colleagues loved the person as much as the writing.

"As a friend, Jon was remarkably warm and understated," said Nick Hayes of Minneapolis, a fellow alumnus of St. John's. "In many respects, I was often impatient with him because I wanted him to be a bit bolder and prouder of his many talents. He had this gift, just as in his writing, of making you rethink a person you thought you knew."

'A twinkle in his eye'

Hayes recalled one incident up north after he bought Hassler's cabin in Nevis. "Be sure to ask the neighbor about where the property line on the dock is," Hassler told him. Hayes did as told, and found himself in the middle of a protracted and sticky property battle -- one that continues to this day.

Even Clare Ferraro, his editor for more than 25 years, will remember a man greater than his works.

"Jon always had a twinkle in his eye," she said. "No matter what his physical problem was, he was indefatigable. He just kept bouncing back."

In addition to his wife, Gretchen, Hassler is survived by sons David Hassler of Alexandria, and Michael Hassler of Brainerd; daughter Elizabeth Hassler Caughey of Brainerd; stepdaughters Catherine Cich of Robbinsdale; Elizabeth Seymour of Richfield; stepson Emil Kresl of Austin, Texas, and five grandchildren.

Visitation will be 4 to 8 p.m. Wednesday at Gill Brothers Funeral Chapel, 5801 Lyndale Av. S. A funeral mass at the Basilica of St. Mary in Minneapolis will be held Thursday at a time to be announced. Burial will be at Lakewood Cemetery in Minneapolis.